Books have been set forth on this issue, and the disquiet and disagreement about where the "hot" slots are placed in a casino are still bubbling – more than 60 yrs after slots were 1st placed in gambling houses.
The traditional rule is that the better one armed bandits were placed just inside the entrance of the casino; so that potential gamblers going by would see real jackpot winners … be stimulated to come inside and play. Our deduction is that this is definitely no longer true.
The majority of the large casinos presently are monstrous complexes … you can no longer see inside from the sidewalk, so there’s no longer a reason to put the ‘loose’ slot machine games near any of the doors.
An additional standard rule is that loose slot machines are located on the major aisles inside the casinos, again so that more potential players could see winning jackpots and be inspired to play. Notably however, we find that this also is no longer a universal rule.
What casinos found over the years is that people walking down the busy aisles were frequently on the way to somewhere else. If they played the slot machines at all, they would simply put in their loose change because they happened to be walking by. Win or lose, they would very often not stop to keep playing. And the very last thing a casino wants is for someone to win a jackpot by playing only a few coins and then not stay to put it all back in!
Nowadays, casinos are constantly changing their perspective about where to place the loose slots.